1. Field of the Invention
The present invention relates to a paper feeding device for feeding manuscripts and copying paper sheets in an image recording apparatus such as a copying machine.
2. Description of the Prior Art
A known such paper feeding device is shown in FIGS. 9, 10 and includes a paper housing member 21 for housing a plurality of paper sheets P in layers. A position controlling means 22 for controlling the positions of leading ends of the paper sheets P is mounted adjacent member 21 so as to be movable to a control-released state only in the first stage of a paper feeding operation by pivoting in a downstream direction with respect to a paper feeding direction. A paper supply roller 27 feeds the uppermost paper sheet P during a paper feeding operation. An upper feed roller 26 and a lower feed roller 26 grasp and convey the thus fed paper sheet P from paper housing member 21 and are located at a position midway along a paper feeding path. A paper feeding roller 23 rotating in the paper feeding direction and a separating roller 24 rotating in a direction opposite to the paper feeding direction are provided to separate a paper sheet beneath the topmost paper sheet which might be fed therewith and to prevent conveyance thereof by rollers 25, 26. Rollers 23, 24 are located upstream in the paper feeding direction with respect to feed rollers 25, 26.
According to the above described construction, advantages occur in that even though the paper housing member 21 is supplied carelessly with the paper sheets P, the leading ends of paper sheets P are caused to be positioned in the correct orientation by the position controlling means 22, so that the paper sheets can be stably fed, even when two paper sheets P are fed simultaneously by the paper feeding roller 23. The lower thus fed paper sheet P is subjected to the action of separating roller 24 in the direction opposite to the paper feeding direction, so that the simultaneous feeding of two paper sheets effectively is prevented. When feeding the top paper sheet P by the feed rollers 25, 26, paper feeding roller 23 and separating roller 24 are spaced from each other (solid lines in FIG. 10), so that the paper feeding force to be applied by the feed rollers 25, 26 can be reduced and the generation of static electricity due to frictional contact between the paper sheet P and paper feeding roller 23 and separating roller 24 can be suppressed.
However, when the paper feeding roller 23 and separating roller 24 are spaced from each other while the paper sheet P is being conveyed by feed rollers 25, 26, the double feed preventing function of the separating roller 24 is lost. Thus, two paper sheets can be fed simultaneously, thereby producing jamming. Even when jamming is not produced, nevertheless, in the case where a manuscript is the object, an image of two pieces of the manuscript, which is in a shifted condition, can be copied on two recording paper sheets, half and half. In the case where a copying paper is the object, an image of a manuscript can be copied on two shifted pieces of copying paper, half and half.